NEW YORK — Does professional tennis have an injury crisis? In the short term, the answer is, surely, yes.

When the US Open begins Monday, it will be missing both last year’s men’s finalists — Stan Wawrinka and Novak Djokovic — on fitness grounds, as well as 2012 champion Andy Murray, 2014 runner-up Kei Nishikori and last year’s Wimbledon finalist Milos Raonic. On the women’s side, 2011 champion Sam Stosur has also withdrawn.

And then you have the multitude of contenders whose build-up to New York has been interrupted or curtailed: Roger Federer, Marin Cilic, Nick Kyrgios and Maria Sharapova.

It is hard to remember a longer or more illustrious injury list. But does it count as firm evidence that tennis is becoming more dangerous for the players? The answer to that one is a good deal murkier.

Milos Raonic waves to the crowd as he walks off the court after losing to Adrian Mannarino at the Rogers Cup on Aug. 9.Paul Chiasson /
CP

The data: imperceptible increases

Since 2012, both men’s and women’s tours have kept computerized medical records for all their players. So we have a decent sample of data points to work with.

From the end of 2014, the ATP logged a small increase, of between one and three per cent, in reported injuries over each of the next two seasons. But if you compare the first three-quarters of this season with the equivalent period in 2016, the numbers have dropped again by some six per cent (the Olympic Games may play a role here), so that we are almost back where we started.

Over the same period, the WTA’s data have also remained stable. Yet since 1994 — and the introduction of the age-eligibility rule that restricts teenagers’ appearances until they reach 18 — median career duration on the women’s tour has risen by two years to achieve an encouraging total of 13.7. That compares more than favourably with American team sports such as football (3.1 years) or basketball (5.5).

The pied piper effect?

Certain tournament directors — especially those whose events are staged towards the end of the year — must have winced when Federer returned from a six-month lay-off to win January’s Australian Open.

Would there be copycats? Did the influence of Federer — as well as that of French Open champion Rafael Nadal — help persuade Djokovic and Wawrinka to close their own 2017 seasons in the days after Wimbledon? The example is such a compelling one that it may even have crossed sports, judging by Rory McIlroy’s recent comments.

In this Jan. 29 file photo, Rafael Nadal (left) and Roger Federer are shown after the Australian Open final.Michael Dodge /
Getty Images

Yet the US Open’s tournament director, David Brewer, argues that these few instances amount to little on their own. “I think it’s a theory in search of something,” Brewer said. “If you ask Roger for his preference, it wouldn’t have been to miss the US Open last year. Same story for Novak and Stan. We know Novak has been dinged up for a year or so, and Stan is having an operation, so they’re all legitimate reasons.”

How about the idea that the players’ energies might be depleted by the time they reach this final furlong of the season, thus making injuries more likely? “We’ve talked about that and we really don’t think so,” Brewer replied. “Tennis is pretty much a 12-months-a-year sport now.”

This last point is supported by Todd Ellenbecker, the ATP’s vice-president for medical services, who says that the clearest spike in the rates of reported injuries comes in January. This could be connected with the intensity of December training blocks — or simply the fact that players don’t have access to ATP physios over the Christmas period, and thus bombard them with queries as soon as they go back to work.

The aging workforce

Could we be missing the most obvious factor of all? Isn’t the number of high-profile absentees the result of an ageing workforce, especially on the men’s side? Most weeks this season, the world’s top 100 has included more than 40 thirty-somethings.

Perhaps the surprising thing is not that these long-serving players are getting hurt — given the way that tissues lose their elasticity over time — but that they are so determined to keep playing anyway. Federer acts as a pied piper here in a different sense.

Ten years ago, his compatriot Wawrinka might well have perceived his recent knee operation as a good reason to draw down the curtain. Now he is probably imagining the possibility of more big paydays ahead.

Stan Wawrinka covers his face after missing a shot against Rafael Nadal in the French Open final on June 11.Christophe Ena /
AP

The lucrative nature of modern tennis leads to more strategic planning and to larger and more professional support teams. In the words of Sergio Gomez-Cuesta, head of science and medicine at Gosling Tennis Academy in Hertfordshire, “Conditioning these days is awesome. It’s the top players’ attention to detail that has enabled them to last this long.”

Yet this only holds the injury rate stable, rather than reducing it. Players such as Murray or Djokovic tend to cash in their extra fitness margin, training even harder in search of that extra one or two per cent on the court.

“I think some players figure out how to take a rest period to heal themselves,” says Mats Wilander, who will be commentating on the US Open for Eurosport. “But others are too afraid of doing that because they are worried about being unable to get back to the top of their game, so they run themselves into the ground.

“I’m not worried about the big picture,” Wilander added, with what could be unwonted optimism. “I think it’s a learning curve and people will realize with Roger and Rafa as examples that there is nothing to worry about. Just take a break when you’re injured and come back in two or three months.”

The way forward

The ATP and WTA tours are already more proactive than you might think. They both supply detailed medical screenings to new players, and identify potential issues before they flare up.

“Prevention is 50 per cent of what we do,” says Kathleen Stroia, the WTA’s vice-president for sports science and medicine. Stroia works with a team of 30 physios (the ATP employs 18) and has also introduced a biomechanical scanning tool that picks up weaknesses in technique or flexibility. She identifies the lower back and pelvis as problem areas for many, while Ellenbecker says hip problems are on the rise among the men.

More research, though, is needed into the effects of surface and ball changes — even though this is technically challenging. “If someone reports an elbow problem at Queen’s,” says Ellenbecker, “has he developed it because of the previous six weeks of extended rallies with heavy balls on clay courts? How can you tell whether it’s really a grass-court injury?

“Having said that, this is an area we are looking at more. Since we started keeping digital medical records, we’ve been concentrating on improving our provision of care on the ground. But now we’re accumulating enough data to start thinking about wider issues: surfaces, balls, three-set versus five-set matches, and all those different parameters.”

Tennis has been asking similar questions over injury rates since the 1970s. Yet changing the culture will not be easy, as many who work in the sport — even some of the medical staff themselves — remain wedded to its intense physicality.

Asked to explain the prevalence of injury bulletins in 2017, Murray’s former physio Jez Green — who now works with 20-year-old wunderkind Alexander Zverev — replied: “I think it’s wear and tear over the years because of the longer and very physical points. It’s impossible to be super-fast forever without the body starting to break down, especially playing five sets.”

So, would Green be in favour of shortening the format? “No way, best-of-five is how it should be, in my opinion,” he replied. “No hiding place, mentally or physically.”